The invention relates to a method of steering a machine on a predetermined route according to the preamble of claim 1 and a device for its execution.
The method is in particular suitable for steering agricultural machines. However, it can also be used in other fields, e.g. for steering building machines.
The document EP 0 821 296 A2 discloses a method which i. a. serves for the purpose of steering an agricultural machine on a predetermined route. According to this method, for position finding of the machine, a differential GPS is used. In order to allow steering of the machine even upon failure of the GPS, further, a dead reckoning navigation system is provided which uses diverse sensors such as wheel sensors, speed sensors, steering angle sensors and direction sensors.
Conventional systems work so that an actual position of the machine and/or an agricultural machine is compared to a desired position and, if there is a difference between the actual value and the desired value exceeding a certain quantity, a control command is output which has the object to return the vehicle to the desired position as quickly as possible. In order to achieve and a sufficiently exact guidance of the vehicle and ensure that, after reaching the desired position, the vehicle is moved on on the predetermined route there are high demands to control and, in particular, control time.
It is the object of the invention to provide a method of steering a machine on a predetermined route which ensures, at a reasonable expenditure, that the machine travels a continuous route which corresponds to the desired route with sufficient accuracy.
This problem is solved by the features of claim 1. According to the invention, a method of steering a machine on a predetermined route is provided, where, by means of an actual position detecting means, the actual position of the machine is detected and is, by means of a comparator, compared to a desired position, wherein, if there is a difference between the actual position and the desired position exceeding a certain quantity, control commands are transmitted to the machine to return same to the predetermined route on a return way. According to the invention, however, the machine is not necessarily returned on the shortest way and the return is not necessarily effected to the desired position from which a deviation was detected, but it can also be effected to another desired position, preferably in the further course of the predetermined route. According to this method, the optimum return way is determined in consideration of the predetermined route which still has to be traveled in the further course and corresponding control commands are transmitted to the machine which return the machine to a desired position on an optimum return way.